1. Field of the Invention
The present invention relates to a sealing ring for sealing the space between two substantially cylindrical, concentric surfaces, for example the outer surface of a spigot end of a pipe and the inner surface of a socket.
2. Description of the Prior Art
A previously known sealing ring of this type comprises a main portion which is adapted sealingly to engage one of the surfaces and a sealing lip, which projects from the main portion and is adapted to engage the other of the two surfaces while being deflected against the main portion. Thereby, the sealing ring is usually of T-shaped cross-sectional shape, the sealing lip being constituted by the web portion of the T-shaped section.
In its active sealing position in the space between the two concentric surfaces the sealing lip is compressed between the main portion of the sealing ring and the other surface, so that the sealing ring defines a portion which is compressed between said surfaces.
A sealing ring of the type described above has proved to be advantageous from the point of view that it constitutes a lip sealing ring as well as a compression sealing ring. Thereby, the sealing ring provides a seal with respect to pressures on both sides of the sealing ring. The sealing ring described above has disadvantages attributable to the fact that the force required for mounting the joint which includes a sealing ring is inconveniently great.